Lubricating system



Dec. 31, 1957 PAPENGUTH 2,818,050

LUBRICATING SYSTEM Filed June 2, 1954 INVENTOR* :91:95 TTOR5EY UnitedStates Patent 2,818,050 LUBRICATING SYSTEM" Loren R. Papenguth, Pontiac,Mich., assignor to General Motors-Corporation, Detroit, Mich., acorporation of Delaware Application June 2, 1954; Serial No. 433,990

12 Claims. (Cl. 123-90) reciprocating motion thereto through associatedpush rodsand valve rockers, the push rod serving also as aconduit forconducting oil from the lifter to the rocker for purposesof lubrication.In prior valve operating linkages of this type is has been customary tosupply oil to the rocker from the engine lubricating pump by meansseparate from the lifter and push rod, and it is one of the objects ofthis invention to eliminate such separate rocker oil feeding meansthrough the use of the lifter (or conventional tappet) and push rod asthe means for delivering oil to the rocker.

While previous proposals have been made to deliver oil from a hydraulicvalve lifter to a valve stem or push rod actuated thereby for purposeseither of lubrication or cooling, it has been found that use of suchmeans to effect lubrication of a valve operating rocker has heretoforeresulted in either an over-supply of oilto the valves at high operatingspeeds with consequent loss through the valve guides to the enginecylinders, or inability to satisfactorily maintain minimum oil deliveryrequirements at which novel restricting means are incorporated to ensuremaintaining desired oil delivery rates to the rocker throughout therange of intended operating speeds.

The means by which these and other objects of the invention are attainedwill be fully understood from the following description having referenceto the drawing, wherein:

Figure l is a cross-sectional view of a portion of an in ternalcombustion engine incorporating a lubricating system in accordance withmy invention wherein engine oil' supplied under pressure to a hydraulicvalve lifter is deh'vered through a hollow push rod to a cylinder headmounted valve rocker.

Figure 2 is an enlarged sectional view similar to Figure" 1 showing theparts of the hydraulic valve lifter and the adjacent portions of theengine'and push rod ingreater de'-' tail.

Figure 3 is a view similar to Figure 2 showing a modified form of thehydraulic valve lifter.

Referring now in detail to Figures 1 and 2 of the" drawing, the engineshown is of the V-type including a cylinder block and crankcase l ineach'side'of which one'or more cylinders 2 are provided audclosed attheir upper ends-by 2,818,050 Patented Dec. 31, 1957 a cylinder lie'ad3. Suitably'journalled in the crankcase is'a camshaft 4' whichoperatively engages a tappet in the form of a" hydraulicvalve lifter 5so as to cause it to reciprocate in a suitable bore 6 formed in thecrankcase. An engine poppet valve 7, reciprocably mounted in thecylinder head andbiase'd to'its closed position by a valve returnspring'S'inconveritional manner, is operatively con-' nected to thelifter 5'by a valve rocker 9 and a hollow push rod 10; The-particularvalve rocker' 9 illustrated is in the form of agenerally channelshapedsheet metal stamping havingdownwardly presenting opposite endsurfaces 11' and 12 in bearing engagement with the upper ends of thevalve" and push rod respectively, and an intermediateupwardlyprese'nting bearing surface 13'journa1ling on a bearing" member14 fixed to the cylinder head by a stud 15 and nut'16.Be'aringsurfaces'12 and 13 are spherically concavetosocke'tably receivethe spherically shaped push roduppe'r en'd'and bearing member 14,respetcively, and the pushrodha's aslidin'g=fit in a guideway 17therefor extending through the cylinder head. The push rod, beingthus'laterally supported andsocketed at its upper end in the'rocker,serves to restrain rotation of the rocker about the axis of'the stud 15"to the extent necessary to maintain the'rocker'end'surface 11 in properbearing engagement'with the 'stem ofthe valve 7.

Referring to Figure 2, the hydraulic lifter comprises acup-shapedcylinder' member 20 having a nesting cupshapedpiston? orplunger member 21 telescopically slidablethereinand defining an oilpressure or cushion chamber 22 betweentheir respetcive closed ends.Within the pressure chamber 22'and biasing the plunger outwardly of thecylinder 20 is a'spring 23. The interior of the plunger 21 formsan' oilreservoir chamber 24 for supplying the pressure chamber 22 throughacheck valve controlled one- Way passage means shown as a port 25 in theplunger end wall controlled by acheck valve in the form of a ball 26.Acage 'surroundingthe' ball and held in place against the bottom: of theplunger by a spring 23' serves to limit the distance to which the ballmay move in opening the port 25; During each lift stroke of the cylinderby the cam 4 oil is trapped in the pressure chamber by the closing ofthecheck valve ball against its seat and the plunger is forced to travelupward with the cylinder, carrying with it the push rod seat 27 and thepush rod 10, which in turncauses the rocker to fulcrum on thebearingmember 14 and-open the valve 7 against its spring 8. During each suchcam liftingandvalve opening stroke a small amount of the oil trapped inthe pressure chamber 22 escapes around the-plunger, which leakage istermed leak-down andis necessary in order to ensure that thevalve 7 mayfully seat on the subsequent return stroke which occurs with continuedrotation of the cam 4. Were it not for this leak-down during eachlifting stroke, and any of the parts of the valve train lengthened dueto increase in temperature, such greater length would hold the enginevalve slightly off its seat on the cylinder head.

After the engine valve' returns to its seat on the cylinder head thelifter plunger spring 23 continues to maintain the lifter cylinder 20 incontact with the surface of the cam 4 while holding the plunger 21 inabutment with the push rod to take out all lash in the system. While thelifter cylinder is regaining its engagement with the base circle of thecam the plunger is therefore moved outwardly of the cylinder tocompensate for allor substantially all ofits leak-down movement inwardlyon the lift stroke. This, results in re-enlarging the cushion chamber 22and oil flowing thereinto past the then opened check valve 26 from the"reservoir chamber 24. Although a major portion of the leak-down oilescaping around the plunger during the lift" stroke re-enters thereservoir chamber through th'e'pluriger' oil inlet opening or ports 28,in' order to ensure that the reservoir chamber is maintained full at alltimes one or more oil inlet openings or ports 29 are provided in theside wall of the lifter cylinder to communicate with the plunger ports28, and these ports 29 in turn are continuously supplied with oil fromthe engine lubricating system via an external groove 30 on the liftercylinder periphery registering with a recess 31 in the lifter guide borewhich is connected with an engine oil gallery 32 by a passage 33.

Above the reservoir 24, the plunger side walls are counterbored fromtheir open end to form an enlargement 34 in which is slidably fitted thepush rod seat 27 which is flanged at its upper end to rest on the openend of the plunger and forms a wall 35 defining the upper limits of thereservoir 24. Centrally of this push rod seat 27 is provided a chamberoutlet port 36 connecting at its lower end with the enlarged lower endof the counterbore 34 and a lower end opening 37 in the push rod 10. Thereservoir chamber face 38 of this wall 35 forms a seat for a generallyplate-like valve 39 which is adapted to abut therewith in restrictingoil flow into the push rod through the outlet 36 for delivery to therocker 9 during operation. The shoulder 40 defining the bottom of thecounterbore 34 provides a stop for this valve 39 to limit its movementinwardly of the plunger away from its seating face In order that thevalve 39 be prevented from totally closing the port 36 when abutting theface 33 the face 38 is provided with a cylindrical curvature and theopposing face 41 of the valve 39 is made substantially flat.

During operation, while the hydraulic lifter is reciprocating to openand close the engine valve 7 as aforesaid and the reservoir chamber 24is maintained filled with engine oil under pressure from the gallery 32,the restricting plate-like valve 39 is normally urged by the reservoiroil pressure into abutment with the push rod seating member face 38,restricting oil delivery to the push rod lit and the rocker 9. Due tothe inertia forces acting on the plate-like valve 39 during itsreciprocation with the lifter, however, it tends to reciprocate withinthe counterbore 34 between the face 38 and the shoulder 40. By suitablyselecting a valve 39 of proper mass weight and selecting a diameter forthe outlet 36, however, the engine speed at which the plate-like valvewill leave its seat on the face 38 can be predetermined for a givenengine oil supply pressure. For example, with an oil pressure of p. s.i., a valve 39 of approximately .030 in. thickness, and a diameter of.060 for the outlet 36, the valve 39 will be found to remain in abutmentwith the face 38 up through a speed of approximately 1600 R. P. M. for aconventional internal combustion engine of a type presently in use.Also, with the surface 38 having a cylindrical curvature of /2 in.radius under the above conditions it has been found that oil will besupplied to the rocker arm 9 at a rate of .2 to 2 gallons per hour, andusing SAE W oil at 80 F. temperature, oil flow to the rocker will beestablished in approximately 7% minutes after starting the engine. Thesefigures are given merely as representative values, and may be in creasedor decreased as desired by changing the outlet opening 36 diameter,valve 39 thickness, oil supply pressure, etc.

In the modified hydraulic valve lifter shown in Figure 3. theconstruction is substantially the same except that the push rod seatmember 270 is provided with a recess 340 for the plate-like valve 390and extends beyond the latter to carry a washer 400 which takes theplace of the shoulder 40 in the Figure 2 construction. This washer maybe secured in any suitable manner to the lower end of the push rod seatmember 270 as by spinning over the lower end thereof as shown at 271.Also in this modification the plate-like valve 390 is formedbarrelshaped, that is its upper and lower faces 391 and 392 have acylindrical curvature, and the abutment or seat ing face 380 therefor onthe member 270 is made sub- 4 stantially flat to prevent total closureof the outlet opening 36.

While only two constructional forms of my invention have been shown forpurposes of illustration, it is appreciated that numerous minor changesin the construe tion and arrangement of the parts may be made withoutdeparting from the spirit and scope of the invention as defined in thefollowing claims.

I claim:

1. In a lubricating system for an engine or the like including areciprocatedly actuated tappet having an oil chamber with an inletopening and an outlet opening, a member externally of the tappet havinga bearing surface in fluid communication with said outlet opening, forconducting oil pressure to said inlet opening, a seat in said chamber atthe chamber end of one of said openings, and an element movable into andout of abutment with said seat for controlling the oil flow to saidbearing surface, said element and seat having their coabuttable surfaceportions extending only partially about the axis of said one openingwhereby said one opening is only partially blocked when said elementabuts said seat.

2. In a lubricating system for an engine or the like including areciprocatedly actuated tappet having an oil chamber with an inlet andan outlet opening, means rcquiring oil delivery from said outlet openingfor lubrication, means for conducting oil under pressure to said inletopening during tappet reciprocation, a seat in said chamber at thechamber end of one of said openings, and an element movable into and outof abutment with said seat for controlling the oil delivery to saidfirst named means, said element and seat having their co-abuttablcsurface portions extending only partially about the axis of said oneopening whereby said one opening is only partially blocked when saidelement abuts said seat.

3. In a lubricating sytem for an engine or the like including areciprocatedly actuated tappet having an oil chamber therein and aseating member externally of and defining an outlet for flow of oil fromsaid chamber, a tappet actuated member seated on said seating member andhaving an oil conducting passage in registry with said outlet, means forintroducing oil under pressure into said chamber for flow through saidoutlet and passage, a seat in said chamber at the chamber end of saidoutlet, and an element movable into and out of abutment with said seatfor controlling the rate of said oil flow, one of said element and seathaving its abuttable surface curved relative to the abuttable surface ofthe other to preclude their abutting engagement extending fully aboutthe axis of said outlet.

4. In a lubricating system for an engine or the like having a bearingsurface, a reciprocatedly actuated tappet having an internal chambersupplied with engine oil under pressure and defined in part by a wall,said wall having an aperture communicating with said bearing sur face,and a plate movable within said chamber and nor mally urged against saidwall by the engine oil pressure to restrict the outward flow of oilthrough said aperture, said plate and wall having their oppositelyfacing surfaces in only partially abuttable relation about the peripheryof the entrance to said aperture so as to prevent the plate fromcompletely closing the aperture at any time.

5. In a lubricating system for an engine or the like including areciprocatedly actuated tappet having an internal chamber supplied withoil under pressure, mechanism having bearing surfaces lubricated withoil from said chamber including a rocker and a hollow push rod drivinglyconnecting said rocker to the tappet and constituting an oil conductorbetween said chamber and said bearing surfaces, a seat for said push rodon the tappet, said seat having an aperture extending into said chamberand communicating with the interior of said push rod, said chamber beingdefined about the entrance to said aperture by a face of substantialwidth, and a valve having a face adapted to abut said entrance definingface and movable into and out of abutment therewith, one of said facesbeing curved about a single axis transverse thereto and the other beingsubstantially flat.

6. The invention defined in claim 5, wherein said curved face is on thevalve.

7. The invention defined in claim 5, wherein a shoulder is provided insaid chamber in spaced relation from said entrance defining face andlimits movement of the valve away from said entrance defining face.

8. In a lubricating system for an engine or the like having a cylinderhead, a valve actuating rocker mounted in the head, driving means forsaid rocker including a hydraulic valve lifter, said valve liftercomprising a cylinder member and a hollow piston member slidable therein having communicating oil inlet ports in their side walls, saidcylinder member having one end closed and defining an oil cushionchamber between said end and the piston member, one-way check valvemeans providing for flow of oil into said cushion chamber from theinterior of the piston, said piston having an oil outlet port connectedfor oil delivery to the rocker, means communicating with said cylinderfor conducting oil under pressure to said cylinder port for delivery tothe interior of the piston through said piston oil inlet port, and avalve within said piston and movable relative thereto into flowrestricting relation with said outlet port in response to oil pressurewithin the cylinder and movable substantially out of flow restrictingrelation against said pressure in response to inertia forces acting onthe valve at a predetermined engine speed.

9. In a lubricating system for a cylinder head mounted valve operatingrocker, a hydraulic valve lifter having an oil pressure chamber and oilsupply chamber therefor having an oil inlet and an oil outlet, meansexternally of said lifter for conducting oil under pressure to saidinlet and from said outlet to said rocker, said lifter having amechanical connection with said rocker including a wall surrounding thechamber end of said outlet, a generally plate-shaped valve adapted toabut said wall and movable out of abutment therewith to respectivelyincrease and decrease the restriction to flow of oil to said outletwithin the chamber, said wall and valve having their co-abuttingsurfaces only partially circumferentially coextensive with each otherabout the chamber end of said outlet whereby when said valve is inabutment with said wall the chamber end of said outlet is only partiallyclosed.

10. In a lubricating system for a cylinder head mounted valve operatingrocker, a cylinder head, a rocker mounted thereon having a bearingsurface, a push rod having one end drivably connected to the rocker,said rocker and push rod having connecting oil passageways forconducting oil to said bearing surface, a hydraulic valve lifterdrivably connected to the other end of said push rod, said lifterincluding slidably interfitted cupshaped cylinder and plunger membershaving their closed and open ends in corresponding relation and definingan oil cushion chamber in series thrust transmitting relation betweentheir closed ends and a reservoir chamber for said cushion chamber,means for conducting make-up oil under pressure to said reservoirchamber from a source externally of said lifter, spring means urging theplunger member outwardly of the cylinder member, check valve meansbetween said members providing for one-way flow of oil to said cushionchamber from said reservoir chamber, a push rod seating member restingon the plunger member open end and having a central aperture connectingsaid reservoir chamber to said push rod passageway, said push rod seathaving a substantially flat surface defining said reservoir chamberabout said aperture, a generally plate-like valve slidably guided by thelaterally defining walls of said reservoir chamber for movement into andout of abutment with said push rod seating member flat surface tovariably restrict oil flow out of said chamber through said aperture,and stop means between said plate-like valve and said check valve meansto limit aperture restriction decreasing movements of said plate valve,said plate-like valve having its surface abuttable with said flatsurface curved about a single axis transverse to said aperture topreclude a total closure of the reservoir chamber end of said aperture.

11. A hydraulic valve lifter constituting a lubricant conductor betweena valve operator and a source of lubricant under pressure, comprisingcooperating cylinder and plunger members defining an oil cushion chamberand an oil reservoir chamber therefor, passage means for conducting oilfrom the reservoir to the cushion chamber, a pressure oil supply inletto the reservoir chamber and an oil delivery outlet leading from thereservoir chamber adapted to be connected to said valve operator, saidreservoir chamber being defined inwardly adjacent said outlet by a valveseating surface, and a valve adapted to abut said seating surface and tomove away thereform within said reservoir chamber, and stop means inoperatively fixed relation to said plunger member between said passagemeans and said outlet to limit movement of said valve away from saidaperture.

12. A hydraulic valve lifter comprising a cylinder adapted to be guidedfor reciprocatory movement, a hollow plunger slidably fitting saidcylinder and cooperating therewith to define an oil cushion chamber inendwise thrust transmitting relation therebet-ween, passage meansconnecting said chamber with the interior of the plunger and otherpassage means for conducting oil under pressure from a point externallyof the lifter to the interior of the plunger, said plunger having a wallprovided with an outlet leading externally of the lifter, and a valvecontrolling the flow of oil through said outlet, said valve beingmovable toward and away from said wall in response to the oil pressureacting on said valve within the plunger and the inertia forces on saidvalve incident to its reciprocatory movement during reciprocation of theplunger and cylinder, and means carried by the plunger and restrictingmovement of the valve away from said wall, said valve and wall havingcooperating abuttable surfaces, one of said surfaces having asubstantial singleaxis curvature relative to the other to ensure againsttotal closure of said outlet at its end interiorly of the plunger.

References Cited in the file of this patent UNITED STATES PATENTS1,930,568 Short Oct. 17, 1933 2,645,215 Moser July 14, 1953 FOREIGNPATENTS 481,811 Great Britain Mar. 18, 1938 536,674 Great Britain May22, 1941 830,433 Germany Feb. 4, 1952

